Switch.



PATBNTED AUG. l5, 1905. F. R.. MGBBRTY. SWITCH.

APPLICATION FILED 1120.21.1903.

No. 79u26.

f l v Q f il w IITED STATES PATENT OFFICE.

FRANK R. MCBERTY, OF EVANSTON, ILLINOIS, ASSIGNOR TO IWESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SWITCH.

Specification of Letters Patent.

Patented Aug. 15, 1905.

To all whom, t may cm1/cern:

Be it known that I, FRANK R. MGBERTY, a citizen of the United States, residing at Evanston, in the county of Cook and State of Illinois, have invented a certain new and useful Improvementin Switches, of which the following is a full, clear, concise, and exact description.

My invention relates to aswitch, and has for its object to provide an improved construction whereby the switch may be protected from injury and from operation by other than authorized persons.

My invention is particularly applicable to spring-jack switches and contemplates an inclosed switch with a guard for preventing access thereto, the guard being locked in position and arranged to be released by a key carried upon the plug or removable part of the switch.

In the accompanying' drawings I have illustrated a plug and spring-jack switch of a type which is adapted for use in connection with telephone-lines extending, for example, alongside a railroad-track to enable an employee provided with a telephone set to plug into any spring-jack and make connection with the line.

Figure lis a sideviewoil my improved springjack, the inclosing case thereof being shown in section. Fig. 2 is a longitudinal sectional view of the spring-jack on line 2 2 of Fig. l. Fig. 3 is a View showing the form of plug I prefer to employ.l Fig. 4 is a side elevation of the spring-jack, showing the plug fullyinserted. Figs. 5 and 6 are detail views showing the manner of engagement of the plug with the movable guard of the spring-jack.

The same letters of reference are used to designate the same parts in each of the figures of the drawings.

The spring-jack shown in the drawings comprises two contact-springs or line-terminals a. a, mounted upon but insulated from a transverse bar I), which is secured to two bolts c c', mounted upon the frame-plate l of the spring-jack. Said frame-plate has an orifice therein adapted to permit access to the contact-springs t a. A guard is mounted to reciprocate upon the bolts of the frame, which serve as guide-rods. Said guard is provided with a tubular projection e, which is adapted when the guard is in its forward position to enter and block the orilice'in said frame-plate (l. A slot or opening e2 extends longitudinally through said tubular projection and through a portion of the body of the guard e. The said tubular projection e' is provided with a shoulder e3, which is adapted when the guard is in its forward position to be engaged by the end of contact-spring a, which thus serves to hold said guard against movement and effectually protects the spring-jack against all harmful agencies. Two spring-detents ff are mounted upon the rear of the guard e and extend forward on either side thereof, the forward extremities of said detents resting above and below the opening e2.

The plug g of my invention consists of tip and sleeve contact portions g g, adapted to engage the contact-springs a a of the springjack, respectively. is formed a key t, having' an inclined shoulder t, a narrow neck, and an enlarged tip The key may be provided with a longitudinal groove It in the side to permit said key to be thrust in the opening' e2 of the guard past a pin e", which projects from the side of the guard 'into the slot l/Vhen the said plug is applied to a spring-jack constructed as above described, the key carried by the plug is forced through the slot or opening c2 of the guard e, and the inclined shoulder /L' of the key raises the end of contact-spring a from its engagement with the shoulder e of the guard. The guard is now unlocked, and the plug may be inserted clear into the springjack, pushing' the guard along the guide-rods c c' to its rear position, as shown in Fig. 5, and permitting the contact parts g' g of the plug to engage the contact-springs a (l. of the spring-jack. When the plug is inserted, the enlarged tip tg of the key is engaged by the spring-detente ff. These detents are provided for the purpose of returning the guard. to its normal position when the plug' is withdrawn. As the plug is pulled out theguard is drawn along with it to the position shown in Fig. l, and when it reaches the end of its journey an increased pull on the end of the plug is necessary to disengage the end of the key from the spring-detents to permit the total removal of the plug from the spring-jack.

It will be apparent that my invention is ca- Upon the tip oi said plug pable of modification, and I do not, therefore, desire to be understood as limiting myself to the exact construction shown.

I claim l. The combination with a spring-jack, of a movable guard for said spring-jack, means for locking said guard in position to prevent access to the spring-jack, and a plug having a key portion adapted to unlock said guard to permit the insertion of the plug.

2. The combination with a spring-jack, of a movable guard normally maintained in position to prevent access thereto, a locking part engaging said guard to hold the same against removal, said guard having an opening', and a plug having a key at its end adapted to be inserted in the opening of said guard and to disengage said locking part from the guard, said guard being adapted when unlocked to be moved to permit the operative engagement of the plug with the spring-jack.

3. The combination with a loop-plug, of a spring-jack having contact-springs adapted to engage corresponding contact portions of said plug, a guard for the orifice ofthe spring-jack slidably mounted in the framework thereof, one of said contact-springs normally engaging' said guard to lock it in position, said guard having a keyhole therein, and a key portion formed at the tip of the plug adapted for insertion in said keyhole and to disengage said contact-spring from the guard, said guard being slid to the rear in inserting' the plug, and a detent carried by the guard adapted to engage the plug, whereby in withdrawing the plug' the guard is pulled back to its normal position and locked by the spring.

4. The combination with a spring -jack switch inelosed in a protecting-case, said case having a plug-hole through which a plug may be inserted, of a guard mounted to slide longitudinally upon the frame of the spring-jack, and normally blocking the plug-hole, a locking part normally holding the guard in position, and a plug carrying a key adapted to disengage said guard from said locking part, an opening being provided for the insertion of said key; the guard when unlocked being adapted to be pushed back in the insertion of the plug. Y

5. The combination with a loop-plug, of a switch provided with two contact-springs, a movable guard for the opening in the switch adapted to be engaged by the plug when inserted and carried back thereby, the contactsprings of the switch being adapted to close one upon each of the contacts of the plug when the guard is carried back from the oritice and out of the path of said springs; said guard by its engagement with the plug being brought back to its normal position on the removal otl the plug.

6. The combination with a spring-jack, of a lock for the same normally preventing access thereto, a plug, and a key carried by the plug adapted to operate said lock to permit the plug to engage with said spring-jack.

7. As a new article of manufacture, a switch-plug having' a key formed at its tip,

said key comprising an inclined Shoulder it',

a narrow neck, and an enlarged tip 7b2.

In witness whereof I hereunto subscribe my name this 14th day of November, A. D. 1903.

FRANK R. MCBERTY.

Vitnesses:

E. F. BEAUBIEN, E. R. SKINNEP.. 

